1. Technical Field
The present invention relates to a mobile device having a camera module and magnetism generating parts different from the camera module.
2. Related Art
Digital cameras employ various types of camera-shake correcting mechanisms for suppressing blur generated on photographed images by jigging of a user's hand. Concerning this matter, refer to Patent Documents 1 (JP Hei. 7-274056 A), 2 (JP 2005-326807 A corresponding to US 2005/0225646 A) and 3 (JP 2612371 B).
In the camera-shake correcting mechanisms described above, some of them adopt a so-called gimbal mechanism in which a holding module which holds a picture-taking lens can be freely rotated in the pitching and the yawing direction.
However, in the gimbal mechanism disclosed in Patent Document 1 described above, it is necessary to arrange four rotary joints, which can be freely rotated, at upper, lower, right and left positions. Therefore, a size of the camera-shake correcting mechanism tends to be increased. When the size of the camera-shake correcting mechanism is forcibly reduced, problems are caused in which bearing portions of the rotary joints become fragile.
Therefore, US 2008/0085108 A, JP 2008-089876 A (corresponding to US 2008/0074504 A), JP 2008-107784 A and JP 2008-092201 A propose a drive structure that supports a pivot point which is one point on an outer circumference of a holding module so as to freely swing. And the drive structure drives the holding module through a first and second drive points which are respectively distant from the pivot point in first and second direction. Further, the Japanese Patent Application No. 2007-035341 (corresponding to U.S. patent application Ser. No. 11/972,525) proposed a technique as an image stabilization unit that enhances the position detecting accuracy of the holding module when the holding module is swinging. When the drive structures proposed in these applications are realized, it becomes possible to manufacture a small camera module even when it has an image stabilization function. Therefore, the camera module can be mounted on a small mobile device.
Operation of the camera module will be briefly explained as follows.
FIG. 10A, 10B, 10C are schematic illustrations for explaining operation of the camera module described above.
FIGS. 10A and 10B show a problem caused in the positional relation between a lens and a sensor when camera shake is generated in the middle of taking a photograph in a usual photographing device. FIG. 10C shows how the camera shake is corrected by the camera module having an image stabilization function.
As shown in FIG. 10A, in the case where no camera shake is generated, even when the camera module is not mounted on the device, an optical axis of the lens and that of the light receiving surface (the sensor surface) of the sensor agree with each other. Therefore, a photographic image is formed at a right position by light from an object. On the other hand, as shown in FIG. 10B, in the case where no image stabilization function is provided, when camera shake is generated, the lens and the sensor face are rotated in the arrow direction. Therefore, the optical axis of the lens and that of the sensor face are shifted from each other and it becomes impossible for the light from the object to form an image at the right position.
Therefore, operation is executed as follows. In the case where camera shake is generated at the time of photographing by a camera module having the image stabilization function which is mounted on a mobile device, as shown in FIG. 10C, the camera module is operated being gyrated, so that the light from an object can always form an image at a right position when the camera module is rotated in an opposite direction even if the mobile device is rotated. When the camera module having the image stabilization function is mounted on the mobile device as described above, even if the mobile device is rotated at the time of photographing, the camera module can be maintained in the same posture as that right before photographing. Therefore, it is possible to take a photograph pleasantly.
In this connection, there is a demand of further reducing in size and thickness of the mobile device recently. Even on the mobile device, the size and thickness of which are reduced, various electronic parts except for the camera module are mounted. Examples of the above electronic parts are magnetism generating elements such as speakers and so forth. On the other hand, on the camera module described above, a hall element, which is a magnetism detecting element for detecting a position of the movable portion so as to correct the image blur, is arranged.
Therefore, when the camera module is mounted at a position close to the speaker at the time of mounting the camera module on the mobile device, the hall element is affected by a magnetic force generated by the magnetism generating element such as a speaker and malfunction might be caused.
In order to prevent the occurrence of the above problem, for example, it is possible to providing a shielding cover. However, when the above shielding cover is provided, the number of parts is increased and further it is required to provide a space in which the shielding cover is arranged, which becomes an obstacle at the time of reducing a size of the mobile device.
The present invention has been accomplished in view of the above circumstances. An object of the present invention is to provide a mobile device, into the housing of which a camera module having an image stabilization function is incorporated, in which no malfunction is caused in the camera module.